AngelOfGrief

Today the engine was disassembled completely. Apart from the timing chain torn, we have 6 valves damaged, IMS sprocket teeth bent and broken (the sprocket which was carrying the broken chain), plastic chain guides worn. No metal parts inside whatsoever, no metal in the oil filter. What's much worse, there is no indication of what caused poor chain tension condition, so the tech guy is kind of clueless. He checked the tensioner and told me he believes it's working. The tensioner is sill under suspicion, but the price is sort of unreasonable (95910505101 - around $400), I don't really know if I should order it along with other parts. It kind of makes sense to replace everything related to timing mechanism: chain, tensioner, sprocket, guides. But from my experience, the "replace everything" method does not work in 80% cases. You have to find the real cause, and eliminate it. Otherwise, it's a waste of time and money... :( If anyone has any ideas, please kindly share.

Well, we have several 996tt's here in our local Porsche Club, but my chain rattle was much louder than on other people's cars. It's actually a long story, my engine was rebuilt about 3 years ago (due to IMS sprocket failure) and developed this rattle after the rebuild. Before the rebuild the chains were perfectly silent. The tech person who worked on the car and also many forum postings presuaded me it was normal, so I drove the car like that for 3 years, and now, here we go, chain failure. <_<

Thanks for the answer. Yes, in fact, we decided to pull the engine and take it apart completely to see what was actually damaged. From what I could find on the net, a broken timing chain may cause severe damage to many engine parts: valves, sprockets and even the IMS, in some cases. So, I guess, it's gonna be a complete engine rebuild, once again. Ah, well...

Hello. Recently I was driving the car as usual and suddenly PSM light went on, then the check engine light, then the engine shut down. I tried to start it but it wouldn't. After several other attempes the engine stopped turning. :o I had the car towed and today took it to the repair shop. Diagnostics showed timing errors in camshaft 1, so the tech removed the left cover to find the timing chain broken. It must be mentioned that I had the infamous 996tt chain rattle, but I kind of thought it was "normal". Turns out, it wasn't... <_< Now, we're up to two options: 1. Try to replace the timing chain without tearing the engine apart. 2. Remove the engine from the car and take it apart to see what's actually damaged inside the engine. Whilst the tech decides which way is better, I am up to buying the timing chain. So, the original part no. is 99610555271, however, there is an OEM part from Iwis, as pelicanparts.com suggests: http://www.pelicanparts.com/cgi-bin/smart/more_info.cgi?pn=996-105-552-71-M48&catalog_description= The Iwis part is really inexpensive. So, after some googling I was able to find the Iwis part no, it's D67ZN-19. Then, I found this document: http://www.iwis.de/uploads/tx_sbdownloader/iwis_Motorsysteme_Automotive_aftermarket_Ersatzteile_DE_EN.pdf So, if possible, could someone please kindly answer these questions for me: 1. Iwis chain comes without the master link, which means it can be replaced w/o tearing the engine apart. How do I order the master link? What is the part no? 2. Does the original timing chain come endless or without the master link? Searching for 99610555271 in google images suggests it does not come endless, however, the oem part in the engine IS endless: 3. The part no. D67ZN-19 according to the PDF above translates into several car models, including 996 carrera, 986 boxster, 996 GT3/GT2/Turbo, even some Mercedes and Peugeot cars. Do these cars really have the same timing chain or is it some kind of error? YOUR HELP WOULD BE GREATLY APPRECIATED. Thank you!!

Here is the manufacturer website for the underdrive crank pulley: http://www.evoms.com/product_p/epk-gt2.htm The idea behind is: it's diameter is smaller, thus it gives us about 10-15 hp on the wheels.

Loren, are you sure the old pulley is balanced with the engine? I've got a feeling it's balanced separately, because it's got its own part number and can be purchased separately. The old pulley is totally messed up: its mounting place is ruined, and also the cyllindrical pin's place, the whole thing is out of balance which can be observed while the engine's running. :(

Well, they actually do have a pulley for the turbo cars, and I was asking about the advantages -- are there any? The "tuned" pulley is slightly smaller diameter, they claim it poses less load on the engine thus increasing horsepower...

Update. It was enough to remove the bumper and the heat shield underneath it and also another small plank to actually get full access to crank pulley and its bolt. We were also able to remove the pulley by removing the belt tensioner (bolt on the back, nut on the front). It turned out the crank pulley is all messed up and needs to be replaced. (( The crankshaft is fine however, luckily. The weird thing is that partnumber on the pulley is misspelled: it reads 996 102 170 71, whereas correct number is 996 102 017 71. For my VIN, PIWIS PET shows p/no 996 102 017 72 that fits all turbo range Porsches 996-997. Should I get any type of a tuned kit like this one? Is it worth it? http://www.amsperformance.com/cart/evoms_porsche-996-997-gt3-lightweight_pulley-kit.html

Thanks for the info. Do you happen to know by any chance: is it possible to access the pulley without lowering the engine and/or removing the muffler?

Hello. My 996tt's crank pulley has gotten loose lately. It fell off and I had to DIY screw it back with the help of my nephew right on the street. We removed the tensioner pulley and screwed the bolt back with a regular wrench. The bolt got a bit damaged, so we filed it a bit to restore the grooves. I was able to drive back to my parking place, expecting to take the car to get serviced later, however yesterday I decided to replace the battery (it died afterwards) and when I started the car and drove it around the parking I heard loud squeaking. Then the 'charge' light went on, steering became heavy: the pulley was loose once again, but I was able to catch the moment: I shut the engine off and the pulley did not fall off, but the crank bolt was loose -- I could see it thru the air filter. I have already gotten a new crank pulley bolt and the cylindrical locking pin also. I am not going to service the car myself, but I have a few questions and I want to make sure the mechanic does it right. 1. What's the deal with the cylindrical pin? It's mentioned in the service manual and there is a cavity for it in the crankshaft and the pulley, but the pin is not shown on PIWIS PET page for 996 turbo engine, only for 996 GT3. Is it supposed to be there, actually? I don't know if it was there originally, since it might have just gotten lost: I haven't found it in the engine compartment. 2. The 996tt service manual does mention the pin, and it also states the bolt has to be tightened to 170 Nm. Does that mean no glue/loctite is to be used? There was no trace of glue on the old bolt. I would appreciate any comment on this, please.

There is no AUX IN in the PCM1, that's for sure, however, there are 3 ways to do it. 1. Use AUX-IN of the CD changer. That would require you to use the line-in connector of the CD changer on a three piece connector on the back of the PCM1 (top connector). You want the blue piece. Then you can use CD changer mode in place of AUX IN, you only need the changer to have CDs. 2. Use cassette in. That would require disassembling the PCM1 (I did it), but that's a tricky way, you probably do not want it. 3. Use some 3rd party CD changer emulator that would trick the PCM1 into thinking it's actually playing CDs. If I were you, I'd stick with option 1. It's easy to do and it cost you nothing. Interesting thing, PCM1 has an AUX RGB input (video) which can be activated by pulling a certain pin to ground, but NO audio AUX-IN.

Thanks, that's what I'm going to do. I consulted a local tech and he said they are having PIWIS delivered from day to day, he also said Porsche diagnostitcs provides extensive fault codes for transmission, so something is sure to come up.

Hello! I own a MY2002 996TT w/ a tiptronic transmission (produced by Mercedes as I hear). I bought the car recently and only driven it around 3K miles this season. Mileage is about 45K. The car was running fine w/o problems whatsoever. Recently, after a long aggressive drive (around 5-6 hrs on a weekend) I was parking the car, I put it in P and left for a few seconds w/ engine running and when I returned to the car, I put in D and it would not engage. The car did not move as though it was in neutral. The dash read "2nd gear" and the engine revved up a bit like usual to compensate for the gear. I moved the gear selector around a bit and after I put it into R it worked fine and I was able to park the car as usual. The problem never emerged for around a week or two (I drive everyday, always aggressively). Yesterday, exactly the same circumstances: a long aggressive drive (6 hrs on a holiday), no problems whatsoever: I did park the car, went to shops, cafes, shut engine down several times -- all was running fine. Then, at the end of the day at the parking lot, when maneuvering around very slowly, I put in R and it would not engage. I had to move the selector around a few times to get it to work. This time, however, I noticed after this fail the gears would engage with a considerate car jerk: both D and R. I parked the car and left and haven't used it since. One important thing to note is: it's a multi-storey underground parking and I have to drive very slowly for around 5-7 minutes with car inclined. Both times problems happened after this drive, never on a driveway or city. Could this somehow cause misfunction? Anyone experienced anything similar? I am first going to take the car for trans fluid level check, maybe have fluid and filter replaced, would that help? There are no leaks whatsoever... Thank You. p.s. I am really upset about this. :( Funny thing is a have an Audi A5 3.2 and it had tiptronics problems too (leaks, no shifting problems however) - costly repairs.

Hi, I own a 996 turbo and would like to fit a reverse camera. I have already modified PCM1 to have NTSC input and a control wire which is hooked to black/blue reverse gear wire. I also purchased an Audi stock reversing camera (p/no 4L0980551) and a cable with quality car FAKRA connectors. What I would like to know is the best place to fit the camera and if anyone could share with me some installation pictures, I'd be very grateful. Most people say it can be fitted in place of one of license plate lights, but I do not like the idea because viewing angle would be too small, also, the way it's fitted, say, on Audi A5 and Infiniti G25 is *above* the bumper, which gives the driver a nice perspective: you can see the obstacles in relation to rear bumper. Somewhere around the LED stop light on the rear spoiler -- a good place? Thanks. :)

If your car was originally equipped with PCM1 nav unit, the black/blue wire is on the nav cdrom connector. BTW connecting reverse wire to a new nav unit *might* be of use, since the stock navigation does use reverse wire for better positioning (along with accelerometer).